As you know, the line length limit of 132 characters was removed in Fortran 2023. The section 6.3.2.1 states about free form:
A line shall contain at most ten thousand characters.
This blog has studied what is the best rotation angle for your screen: indeed, on Linux you are not limited to 0°, 90°, 180°, 270°. The new free form can benefit from this free angle setting. This developer has shown that the best angle for long lines depends on the diagonal of your screen. In her case, 22° proved to be the best angle:
So this here I think is the best monitor orientation for software development. It provides the longest line lengths and no longer need to worry about that pesky 80 column limit.